I have a flat 400x400 pixels image which represents an area of 400x400 kilometers. I need to draw this image as an overlay on my OpenLayers mapping system. I use OpenStreetMap/Google Maps as base layers. I want to draw the overlay image using an Image Layer and I want to center my overlay image at a specific lat/lon point. The projection of the base layer is EPSG:900913 which is, in fact, the projection used by OpenStreetMap and Google Maps.
What I have understood (please correct me if I'm wrong), is that I can't use a flat, 'unprojected' image as an Image Layer, but I have to do a sort of 'reprojecting' to adjust the image to be compliant with the projection of the map, which is EPSG:900913. Searching here and the net, it seems I should use a library/tool called GDAL to do this, but whereas I am completely new to this I ask you:
- Can anyone address me on how to use it?
- Could you possibly tell me if what I have just said is correct and the way I described here is valid?
- How could I use gdal to translate my flat unprojected 400x400 pixels image to an image projected in EPSG:900913, and suitable to be put as an Image Layer as an overlay?